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Subject[RFC PATCH 3/3] PCI: iproc: Add dma reserve resources to host
Date
IPROC host has the limitation that it can use
only those address ranges given by dma-ranges
property as inbound address.
So that the memory address holes in dma-ranges
should be reserved to allocate as DMA address.

All such reserved addresses are created as resource
entries and add to dma_resv list of pci host bridge.

These dma reserve resources created by parsing
dma-ranges parameter.

Ex:
dma-ranges = < \
0x43000000 0x00 0x80000000 0x00 0x80000000 0x00 0x80000000 \
0x43000000 0x08 0x00000000 0x08 0x00000000 0x08 0x00000000 \
0x43000000 0x80 0x00000000 0x80 0x00000000 0x40 0x00000000>

In the above example of dma-ranges, memory address from
0x0 - 0x80000000,
0x100000000 - 0x800000000,
0x1000000000 - 0x8000000000 and
0x10000000000 - 0xffffffffffffffff.
are not allowed to use as inbound addresses.
So that we need to add these address range to dma_resv
list to reserve their IOVA address ranges.

Signed-off-by: Srinath Mannam <srinath.mannam@broadcom.com>
---
drivers/pci/controller/pcie-iproc.c | 49 +++++++++++++++++++++++++++++++++++++
1 file changed, 49 insertions(+)

diff --git a/drivers/pci/controller/pcie-iproc.c b/drivers/pci/controller/pcie-iproc.c
index 3160e93..43e465a 100644
--- a/drivers/pci/controller/pcie-iproc.c
+++ b/drivers/pci/controller/pcie-iproc.c
@@ -1154,25 +1154,74 @@ static int iproc_pcie_setup_ib(struct iproc_pcie *pcie,
return ret;
}

+static int
+iproc_pcie_add_dma_resv_range(struct device *dev, struct list_head *resources,
+ uint64_t start, uint64_t end)
+{
+ struct resource *res;
+
+ res = devm_kzalloc(dev, sizeof(struct resource), GFP_KERNEL);
+ if (!res)
+ return -ENOMEM;
+
+ res->start = (resource_size_t)start;
+ res->end = (resource_size_t)end;
+ pci_add_resource_offset(resources, res, 0);
+
+ return 0;
+}
+
static int iproc_pcie_map_dma_ranges(struct iproc_pcie *pcie)
{
+ struct pci_host_bridge *host = pci_host_bridge_from_priv(pcie);
struct of_pci_range range;
struct of_pci_range_parser parser;
int ret;
+ uint64_t start, end;
+ LIST_HEAD(resources);

/* Get the dma-ranges from DT */
ret = of_pci_dma_range_parser_init(&parser, pcie->dev->of_node);
if (ret)
return ret;

+ start = 0;
for_each_of_pci_range(&parser, &range) {
+ end = range.pci_addr;
+ /* dma-ranges list expected in sorted order */
+ if (end < start) {
+ ret = -EINVAL;
+ goto out;
+ }
/* Each range entry corresponds to an inbound mapping region */
ret = iproc_pcie_setup_ib(pcie, &range, IPROC_PCIE_IB_MAP_MEM);
if (ret)
return ret;
+
+ if (end - start) {
+ ret = iproc_pcie_add_dma_resv_range(pcie->dev,
+ &resources,
+ start, end);
+ if (ret)
+ goto out;
+ }
+ start = range.pci_addr + range.size;
}

+ end = ~0;
+ if (end - start) {
+ ret = iproc_pcie_add_dma_resv_range(pcie->dev, &resources,
+ start, end);
+ if (ret)
+ goto out;
+ }
+
+ list_splice_init(&resources, &host->dma_resv);
+
return 0;
+out:
+ pci_free_resource_list(&resources);
+ return ret;
}

static int iproce_pcie_get_msi(struct iproc_pcie *pcie,
--
2.7.4
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